PIC Questions

[xxalexx at ix.netcom.com]

> PIC Group,
> 
> I was looking thru the Tech America sale flyer and I saw a cheap device, probably
> a PIC, that would turn a PC into a 'scope, sampling (at 71hz ?) and playing back
> thru the parallel port. How about someone building one so that we can sample the
> O2 sensor and MAP from a running efi system. I think it would be teriffic for the
> 332 project (or has someone already done that?). I would like to see the trace of
> the O2 sensor to determine if you can see each exhaust pulse, and if so, what
> pieces (formula?) to monitor to determine AFR.
> 
> The same for the MAP sensor... can you see the valves open and close??? Some have
> to restrict the map sensor line to get the engine to run correctly.....
> especially with a radical camshaft.. What reading do we use for the EFI????
> 
The price of data acq. is dropping fast.  
ADNAV Electronics, Lake Jackson, Tx
409-292-0988 has a 8 ch. 12 bit A/D, 2 12 bit D/A,
8 ? I/O lines, 2 current sources and a current mirror 
for $99.  that uses printer port.
I bought there 1st model a few years ago, was just
1 ch. 12-bit but never have used it.  I think they
also have kits.
The filtering circuits and sampling times would be helpful
to document.  The O2 signal for me has been fairly clean
with no filtering, I get good readings hooked up straight to PIC.
A GM TPS was very noisy.
I was looking at O2 sensor readings for cyl. misfire, but
but thru out all data due to lack of interest and disk space. 
There seemed to be some patterns, I would like to do something
with DSP and rapid response micro-machined pressure sensors.  
alex